Fuel injection valve for internal combustion engines

Abstract

A fuel injection valve having a valve body, in which a bore with a pistonlike valve member disposed in it is embodied, which valve member is longitudinally displaceably in the bore counter to a closing force and by its longitudinal motion controls at least one injection opening, through which fuel can be injected into the combustion chamber of the engine. A valve holding body is braced axially against the valve body. An inlet conduit, which carries fuel at high pressure, extends through the valve holding body and its contact face, embodied as a high-pressure sealing face, on the valve body as far as the injection openings. The bracing of the valve holding body against the valve body is effected by means of a lock nut, which grips the valve body and with a female thread engages a male thread embodied on the valve holding body. The contact flank of the male thread and the contact flank of the female thread, which are pressed against one another by the bracing, are embodied substantially perpendicular to the longitudinal axis of the male thread, so that upon the bracing of the lock nut, no substantial radial forces oriented outward against the lock nut result.

I claim:  
     
       1. A fuel injection valve for internal combustion engines, having a valve body ( 3 ) in which, in a bore ( 7 ), a valve member ( 10 ) is longitudinally displaceable counter to a closing force by subjection of a pressure shoulder ( 16 ) to pressure by fuel, and by means of the longitudinal motion controls at least one injection opening ( 22 ), and having a valve holding body ( 1 ), which is braced in the axial direction by means of a lock nut ( 5 ) against the valve body ( 3 ), wherein the lock nut ( 5 ) has a female thread ( 44 ) which engages a male thread ( 42 ) that is embodied on an outer jacket face of the valve holding body ( 1 ) or an outer jacket face of the valve body ( 3 ) and has a longitudinal axis ( 8 ), and having an inlet conduit ( 12 ) extending in the valve holding body ( 1 ) and in the valve body ( 3 ), through which conduit, fuel can be carried at high pressure to the at least one injection opening ( 22 ) by means of a contact face, embodied as a high-pressure sealing face ( 30 ) of the valve body ( 3 ) on the valve holding body ( 1 ), the improvement wherein contact flanks ( 50 ;  52 ) of the female thread ( 44 ) and the male thread ( 42 ), respectively, are pressed against one another to effect bracing of the valve body ( 3 ) against the valve holding body ( 1 ), the contact flanks ( 50 ;  52 ) being embodied at least approximately perpendicular to the longitudinal axis ( 8 ) which is surrounded by the male thread ( 42 ) and the female thread ( 44 ). 
     
     
       2. The fuel injection valve of  claim 1 , wherein a shim ( 6 ) is disposed between the valve body ( 3 ) and the valve holding body ( 1 ). 
     
     
       3. The fuel injection valve of  claim 1 , wherein the contact flank ( 50 ) of the female thread ( 44 ) and the contact flank ( 52 ) of the male thread ( 42 ) form an angle within the range of about 85° to 95° with the longitudinal axis ( 8 ).